Potensi Bakteri Penambat Nitrogen Hidup Bebas Sebagai “ Plant Growth Promoting Rhizobacteria"

Bakteri Penambat Nitrogen (BPN) hidup bebas merupakan rhizo bakteri yang mempunyai kemampuan dalam memacu pertumbuhan tanaman (“Plant growth promoting rhizobacteria”) dan berpotensi sebagai pupuk hayati.Telah dilakuakan isolasi BPN dari daerah perakaran tanaman padi, dan diuji kemampuannya dalam melarutkan fosfat (organic dan anorganik), produksi IAA (“indole-3- acetic acid”) dan1-aminocyclopropane-1-carboxylate (ACC) deaminase (kualitatif) dalam kondisi in-vitro di laboratorium Mikrobiologi-Puslit Biologi-LIPI.Tujuan percobaan adalah untuk mendapatkan isolat yang mempunyai potensi sebagai PGPR dan dapat dimanfaatkan sebagai pupuk hayati dalam menunjang pertanian ramah lingkungan/organik. Isolasi bakteri tanah menggunakan media agar manitol Ashby dan Okon, sedangkan media Pikovskaya cair dengan 0.5 persen Ca3(PO4)2 digunakan untuk mengukur pelarutan fosfat anorganik dan organik. Aktivitas IAA dan ACC deaminase menggunakan media LB. Hasil menunjukkan semua isolat yang diuji positif mempunyai aktivitas ACC diaminase, dengan produksi IAA (27,20 – 83,51 µg/mL) dan dapat melarutkan fosfat anorganik dan organik masing-masing berkisar antara 3,31 – 9,76 µg/mL dan 98,28 – 419.80 µg/mL p-nitrophenol/jam.Kata kunci: BakteriPenambat Nitrogen, IAA, ACC) deaminase, PelarutanfosfatABSTRACTFree-living Nitrogen-fixing bacteria (BPN) is a rhizobacteria that have the ability to promote the growth of the plant (\"Plant growth promoting rhizobacteria\") and have potential as a biofertilizer. BPN were isolated from rhizosphere of rice plant, and were tested for their ability to dissolve phosphate (organic and inorganic), production of IAA (\"indole-3-acetic acid\") and 1-aminocyclopropane-1-carboxylate (ACC) deaminase (qualitative) in-vitro conditions at the laboratory of Microbiology-Research Center for Biology-LIPI. The purpose of the experiment is to obtain isolates that have potential as PGPR and can be used as a biofertilizer in supporting organic agriculture. Isolation of soil bacteria using mannitol agar media Ashby and Okon, while Pikovskaya liquid medium with 0.5 persen Ca3 (PO4) 2 is used to measure the dissolution of inorganic and organic phosphate. ACC deaminase activity and the IAA using media LB. Results showed all isolates tested positive has diaminase ACC activity, with the production of IAA (27.20 to 83.51 ug / mL) and can dissolve inorganic and organic phosphates about 3.31 to 9.76 ug / mL and 98.28 - 419.80 ug / mL p-nitrophenol / hour respectively. Prosiding Seminar Nasional Perhimpunan Biologi Indonesia cabang Jakarta. 2016.